>>I'd avoid the complication altogether and use Inno setup - it allows you to choose among a dozen of compression modes, so you don't need any special unzipping etc, it does it on the fly. And it's, IMO, much easier to control than IS or ISLE or whatever it's called this week.
>
>I wish I could do that :) The problem is that it is not "my" application and I did not create the install project. I just somehow was placed in charge of getting the install ready for download on the internet and instead of explaining to the webdesigner how to unzip a zip file I think it is easier to create a self-extracting zip rather than a regular zip file.

I had to do pretty much the same recently - got the old install and the SE scripts, and translated it all into an Inno script. And I've seen the app only once before this. And it works.

Sure, having the old script helped a lot :).